THE FUNGI WHICH CAUSE PLANT DISEASE 353 



EndophyUum L6viell6 (p. 342) 



The cycle of development includes only pycnia and telia, both 

 subepidermal. 



O. Pycnia deep-seated, somewhat erumpent, flask-shaped, with 

 ostiolar filaments. 



III. Telia bvdlate, definite, round, pulverulent. Peridium evan- 

 escent, cells resembling spores but flattened. Spores catenulate or 

 seemingly compacted without order, 1-celled, globoid to ellip- 

 soid; wall colored, medimn thick, verrucose. 



E. semp.ervivi (Alb. & Schw.) D. By. 



Pycnial and telial stages on species of Sempervivum. Myce- 

 liiun perermial in the host. 



Pucciniaceae (p. 335) 



Teliospores stalked (stalk sometimes short or evanescent) 

 1-celled or with several cells in a row or several united to form a 

 parasol-like head on a compound stalk; separate or gelatinous- 

 embedded. Basidiospores formed from promycelia. ^Ecia with 

 or without peridia. Urediniospores solitary. 



This is the largest and most important family of the order, in- 

 lesting numerous valuable agricultural plants and causing enor- 

 mous loss. The species are manifold and the complexities owing to 

 polymorphism, hetercecism and biologic specialization are very 

 great. 



Key to Genera of Pucciniacese 



Teliospores united into a head on compound 

 pedicles, or several sessile or stalked on 

 a common simple pedicel; sori subcutic- 

 ular or subepidermal; uredinia when 

 present without peridium or encircling 

 paraphyses. 

 Teliospores united into a head on a com- 



poimd pedicel 1. Ravenelia. 



Teliospores free, 1-4 on a simple pedicel, 

 all but one lateral 

 Teliospores flattened laterally 2. Dicheirinia. 



